Floating clot retrieval device for removing clots from a blood vessel

ABSTRACT

A clot removal device including an elongated member including a distal end; and an expandable frame including a proximal end, and one or more frame members including one or more pinching cells operable to be slidably and rotatably placed thereon, each of the pinching cells including a collapsed state within a microcatheter and an expanded state distal of the microcatheter configured to tweeze at least a portion of a clot.

FIELD

The present disclosure generally relates to devices and methods forremoving blockages from blood vessels during intravascular medicaltreatments.

BACKGROUND

Clot retrieval devices are used in mechanical thrombectomy forendovascular intervention, often in cases where patients are sufferingfrom conditions such as acute ischemic stroke (AIS), myocardialinfarction (MI), and pulmonary embolism (PE). Acute obstructions mayinclude clot, misplaced devices, migrated devices, large emboli and thelike. Thromboembolism occurs when part or all of a thrombus breaks awayfrom the blood vessel wall. This clot (now called an embolus) is thencarried in the direction of blood flow. An ischemic stroke may result ifthe clot lodges in the cerebral vasculature. A pulmonary embolism mayresult if the clot originates in the venous system or in the right sideof the heart and lodges in a pulmonary artery or branch thereof. Clotsmay also develop and block vessels locally without being released in theform of an embolus—this mechanism is common in the formation of coronaryblockages. There are significant challenges associated with designingclot removal devices that can deliver high levels of performance. First,there are a number of access challenges that make it difficult todeliver devices. In cases where access involves navigating the aorticarch (such as coronary or cerebral blockages) the configuration of thearch in some patients makes it difficult to position a guide catheter.These difficult arch configurations are classified as either type 2 ortype 3 aortic arches with type 3 arches presenting the most difficulty.

The tortuousity challenge is even more severe in the arteriesapproaching the brain. For example it is not unusual at the distal endof the internal carotid artery that the device will have to navigate avessel segment with a 180° bend, a 90° bend and a 360° bend in quicksuccession over a few centimeters of vessel. In the case of pulmonaryembolisms, access is through the venous system and then through theright atrium and ventricle of the heart. The right ventricular outflowtract and pulmonary arteries are delicate vessels that can easily bedamaged by inflexible or high profile devices. For these reasons it isdesirable that the clot retrieval device be compatible with as lowprofile and flexible a guide catheter as possible.

Second, the vasculature in the area in which the clot may be lodged isoften fragile and delicate. For example neurovascular vessels are morefragile than similarly sized vessels in other parts of the body and arein a soft tissue bed. Excessive tensile forces applied on these vesselscould result in perforations and hemorrhage. Pulmonary vessels arelarger than those of the cerebral vasculature, but are also delicate innature, particularly those more distal vessels.

Third, the clot may comprise any of a range of morphologies andconsistencies. Long strands of softer clot material may tend to lodge atbifurcations or trifurcations, resulting in multiple vessels beingsimultaneously occluded over significant lengths. More mature andorganized clot material is likely to be less compressible than softerfresher clot, and under the action of blood pressure it may distend thecompliant vessel in which it is lodged. Furthermore, the inventors havediscovered that the properties of the clot may be significantly changedby the action of the devices interacting with it. In particular,compression of a blood clot causes dehydration of the clot and resultsin a dramatic increase in both clot stiffness and coefficient offriction.

The challenges described above need to be overcome for any devices toprovide a high level of success in removing clot and restoring flow.Existing devices do not adequately address these challenges,particularly those challenges associated with vessel trauma and clotproperties.

SUMMARY

It is an object of the present design to provide devices and methods tomeet the above-stated needs. It is therefore desirable for a clotretrieval device to remove clot from cerebral arteries in patientssuffering AIS, from coronary native or graft vessels in patientssuffering from MI, and from pulmonary arteries in patients sufferingfrom PE and from other peripheral arterial and venous vessels in whichclot is causing an occlusion.

In some examples, the device includes pinch features configured forplacement proximate an occlusion (e.g., in the mid internal carotidartery (ICA)). The device can be configured to reperfuse a vessel and/orremove a clot that has a fibrin core. In some examples, the fibrin corecan be in a mid- or distal-position in the clot surrounded by relativelysoft thrombus.

In some examples, the device can be configured to remove a clot in theM1 bifurcation.

In some examples, the device can be configured to remove a clot in theM2 bifurcation.

In some examples, the device can include an elongated member including adistal end; and an expandable frame having a proximal end, and one ormore frame members having one or more pinching cells operable to beslidably and rotatably placed thereon. Each of the pinching cells caninclude a collapsed state within a microcatheter and an expanded statedistal of the microcatheter operable to tweeze at least a portion of aclot.

In some examples, the one or more pinching cells can include a pluralityof strut members operable to actuate and tweeze the clot from a bloodvessel between the plurality of strut members.

In some examples, the plurality of strut members can be positioned aboutone or more central strut members, each strut member joined at commonrespective proximal and distal ends.

In some examples, each of the one or more pinching cells can be operableto tweeze the clot on movement from the collapsed state to a clotpinching state of the expanded state until a portion of the clot iscompressed between the plurality of strut members.

In some examples, a ratio of diameters of each of the one or morepinching cells between the collapsed state and expanded state can befrom approximately 1.5:1 to 4:1.

In some examples, each of the one or more pinching cells can include aradiopaque marker.

In some examples, the one or more pinching cells can include a pinchingstructure including a plurality of strut members and one or more centralstrut members; a first collar having a first collar lumen; and a secondcollar having a second collar lumen.

In some examples, one or more strut members can be a network of strutsoperable to tweeze with at least a portion of a clot, the network ofstruts can be configured such that in an expanded state at least aportion of the network of struts penetrate the clot.

In some examples, the first collar lumen and the second collar lumen canbe operable to receive one or more frame members.

In some examples, an elongated member having a distal end; and whereinthe distal end of the elongated member can be attached to the proximalend of the expandable frame.

In some examples, the one or more pinching cells can be selectivelyaligned in a plurality of orientations on one or more frame members.

In some examples, the expandable frame is generally a wave patternhaving an increasing amplitude along its length.

In some examples, a method for removing a clot is disclosed. The methodcan include deploying an expandable frame into a deployed configurationfrom a delivery configuration within a blood vessel and proximate aclot. The expandable frame can include one or more frame members and oneor more pinching cells located on the one or more frame members. Each ofthe pinching cells can include a collapsed state within a microcatheterand an expanded state distal of the microcatheter configured to pinch atleast a portion of the clot, the expandable frame deployed such that oneor more pinching cells can be in contact with the clot. The method caninclude advancing a lumen of the microcatheter over the expandable framesuch that a portion of the expandable frame at least partially collapsesinto the lumen of the microcatheter, and one or more pinching cells atleast partially collapses into the lumen of the microcatheter. Themethod can include pinching the one or more pinching cells in contactwith the portion of the clot on movement from the collapsed state to aclot pinching state of the expanded state until a portion of the clotcan be compressed between at least a pair of strut members of the one ormore pinching cells; and while pinching the one or more pinching cellswithdrawing the microcatheter, the expandable frame, and the clot.

In some examples, the pair of strut members can be operable to actuateand tweeze the clot from a blood vessel between the pair of strutmembers.

In some examples, the pair of strut members can be positioned about oneor more central strut members, each strut member joined at commonrespective proximal and distal ends.

In some examples, a method for manufacturing the device is disclosed.The method can include forming one or more pinching cells from ashape-memory alloy tube. Each of the one or more pinching cells caninclude a plurality of strut members operable to pinch a clot, theplurality of strut members positioned about one or more central strutmembers, each strut member joined at common respective proximal anddistal ends. The method can include forming at least a portion of anexpandable frame having a proximal end and one or more frame members.The method can include assembling the one or more pinching cells with atleast a portion of the expandable frame.

In some examples, forming one or more pinching cells from a shape-memoryalloy tube can include cutting the shape-memory alloy tube into aplurality of segments; cutting a pattern into a segment of the pluralityof segments; attaching a radiopaque marker to each of the one or morepinching cells; and shape setting a plurality of strut members and oneor more central strut members of a pinching structure to memorize anexpanded state of the pinching structure, a ratio of diameters of eachof the one or more pinching cells between a collapsed state and theexpanded state can be from approximately 1.5:1 to 4:1.

In some examples, forming at least a portion of the expandable frame caninclude constructing one or more frame members on a mandrel; shaping,based at least in part on the mandrel, one or more frame members tomemorize a deployed configuration of the expandable frame; andconnecting one or more frame members to form a distal end of theexpandable frame.

In some examples, assembling the one or more pinching cells with atleast a portion of the expandable frame can include sliding one or morepinching cells over one or more frame members; and connecting one ormore frame members to form a proximal end of the expandable frame,wherein one or more pinching cells can be selectively aligned in aplurality of orientations.

In some examples, the one or more pinching cells can include a firstcollar having a first collar lumen; a second collar including a secondcollar lumen; and wherein the first collar lumen and the second collarlumen can be operable to receive one or more frame members, and whereinthe plurality of strut members and one or more central strut members canbe a network of struts operable to engage with at least a portion of aclot. The network of struts can be configured such that in an expandedstate at least a portion of the network of struts penetrate the clot.

Other aspects and features of the present disclosure will becomeapparent to those of ordinary skill in the art, upon reviewing thefollowing detailed description in conjunction with the accompanyingfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further aspects of this disclosure are further discussedwith the following description of the accompanying drawings, in whichlike numerals indicate like structural elements and features in variousfigures. The drawings are not necessarily to scale, emphasis insteadbeing placed upon illustrating principles of the disclosure. The figuresdepict one or more implementations of the inventive devices, by way ofexample only, not by way of limitation. It is expected that those ofskill in the art can conceive of and combining elements from multiplefigures to better suit the needs of the user.

FIG. 1A depicts a close-up view of an example pinching cell.

FIG. 1B illustrates the movement of an example pinching cell on a wire.

FIG. 2A illustrates an example clot removal device in a deployedconfiguration.

FIG. 2B illustrates an example clot removal device in a deliveryconfiguration.

FIG. 3 is a flowchart that illustrates a method for removing a clot.

FIG. 4A depicts a close-up view of an example clot removal devicepenetrating a clot.

FIG. 4B depicts a close-up view of an example clot removal devicepinching a clot.

FIG. 4C depicts a close-up view of an example clot removal devicecapturing a clot.

FIG. 5 depicts an example frame pattern for an example clot removaldevice.

FIG. 6 depicts an example frame pattern for an example clot removaldevice.

FIGS. 7A-B depict an example frame pattern for an example clot removaldevice.

FIGS. 8A-B depicts an example frame pattern for an example clot removaldevice.

FIG. 9 illustrates an example clot fragment collection section.

FIG. 10 is a flowchart that illustrates a method manufacturing a clotremoval device.

FIGS. 11A-C illustrates pinching cells in a) an expanded state, b) acollapsed state, c) a pinched state of the expanded state.

FIGS. 12A-D illustrate example pinching cell according to aspects ofthis disclosure.

DETAILED DESCRIPTION

Specific examples of the present disclosure are now described in detailwith reference to the Figures, where identical reference numbersindicate elements which are functionally similar or identical. Theexamples address many of the deficiencies associated with traditionalcatheters, such as inefficient clot removal and inaccurate deployment ofcatheters to a target site.

Accessing the various vessels within the vascular, whether they arecoronary, pulmonary, or cerebral, involves well-known procedural stepsand the use of a number of conventional, commercially-availableaccessory products. These products, such as angiographic materials andguidewires are widely used in laboratory and medical procedures. Whenthese products are employed in conjunction with the system and methodsof this disclosure in the description below, their function and exactconstitution are not described in detail.

The following detailed description is merely exemplary in nature and isnot intended to limit the disclosure or the application and uses of thedisclosure. Although the description of the disclosure is in many casesin the context of treatment of intracranial arteries, the disclosure mayalso be used in other body passageways as previously described.

It will be apparent from the foregoing description that, whileparticular embodiments of the present disclosure have been illustratedand described, various modifications can be made without departing fromthe spirit and scope of the disclosure. For example, while theembodiments described herein refer to particular features, thedisclosure includes embodiments having different combinations offeatures. The disclosure also includes embodiments that do not includeall of the specific features described. Specific embodiments of thepresent disclosure are now described in detail with reference to thefigures, wherein identical reference numbers indicate identical orfunctionality similar elements. The terms “distal” or “proximal” areused in the following description with respect to a position ordirection relative to the treating physician. “Distal” or “distally” area position distant from or in a direction away from the physician.“Proximal” or “proximally” or “proximate” are a position near or in adirection toward the physician.

Accessing cerebral, coronary and pulmonary vessels involves the use of anumber of commercially available products and conventional proceduralsteps. Access products such as guidewires, guide catheters, angiographiccatheters and microcatheters are described elsewhere and are regularlyused in catheter lab procedures. It is assumed in the descriptions belowthat these products and methods are employed in conjunction with thedevice and methods of this disclosure and do not need to be described indetail.

The following detailed description is merely exemplary in nature and isnot intended to limit the disclosure or the application and uses of thedisclosure. Although the description of the disclosure is in many casesin the context of treatment of intracranial arteries, the disclosure mayalso be used in other body passageways as previously described.

FIG. 1A depicts a close-up view of an example pinching cell 100.Pinching cell 100 can be configured to embed and/or engage with and gripa clot to retain it securely for retraction. It is understood that eachof the herein described pinching cells can be used interchangeably withclot retrieval devices as needed or required. Pinching cell 100 caninclude a first collar 102, a first lumen 104, a second collar 106, anda second lumen 108 between which a pinching structure 110 is positioned(e.g., between the first collar and second collar). The pinchingstructure 110 can include strut members 112 a, 112 b, 112 c and 112 d.One or more of strut members 112 a, 112 b, 112 c and 112 d can beconfigured as bowed or otherwise including tensioned flex so as to becapable of embedding in a clot and then being actuated to grip and/orpinch the clot during use. The terms “bowed” is intended to refer to astrut that is generally a shape of an arc, while “tension flex” isintended to refer to a strut that has been placed in tension andplastically deformed into a desired shape.

In some examples, pinching cell 100 can be actuated into a pinched stateof an expanded state by being unsheathed from a sheath (e.g., amicrocatheter), by being pulled, or actuated by one or more pullmembers, delivering a current to one or more of strut members 112 a, 112b, 112 c and 112 d to cause at least a first portion of the one or moreof strut members 112 a, 112, 112 c and 112 d to change from an expandedstate to pinched state. The pinching cell 100 can be configured to embedand grip, pinch, and/or “tweeze” the clot, as shown and described moreparticularly in FIGS. 11A-C. As discussed herein, the term “tweeze” or“tweezing” is intended to refer to the sheathing of the pinching orsqueezing cells that causes respective struts to come together andtweeze or grip at least a portion of clot. In this respect, while thenumbers of struts in a respective cell need not be limited, at least twostrut surfaces can be included so as to tweeze corresponding clotmaterial. One or more of strut members 112 a, 112 b, 112 c, and 112 dcan also have one or more radiopaque bands to indicate to the user whenthe pinching cell 100 is pinched, as the distance between struts isdecreased when the pinching cell 100 transitions from the expanded stateto the pinched state of the expanded state.

The diameter of pinching cell 100 can range between approximately 2-10millimeters depending on how much the design profile allows. Onepreferred diameter can be approximately 2.25 millimeters. In someexamples, pinching cells 100 can be small enough to fit in a 0.021 or0.018 inch ID microcatheter.

The pinching cell 100 can be constructed from a superelastic materialsuch as Nitinol or an alloy of similar properties. The material could bein many forms such as wire or strip or sheet or tube. A particularlysuitable manufacturing process is to laser cut a Nitinol tube and thenheat set and electropolish the resultant structure to create a frameworkof struts. This framework can be any of huge range of shapes asdisclosed herein and may be rendered visible under fluoroscopy throughthe addition of alloying elements (e.g., Platinum) or through a varietyof other coatings or marker bands. Pinching cell 100 can include acollapsed state for delivery and an expanded state distal of amicrocatheter for clot retrieval, flow restoration and/or fragmentationprotection. To move between the collapsed state and the expanded state,the pinching cell 100 can be configured to self-expand upon deliveryfrom a microcatheter (e.g., release from the microcatheter) to anexpanded diameter, as discussed in detail in FIGS. 11A-C.

Turning to FIG. 1B, an example pinching cell 100 is shown placed on awire 114 that can pass through the first lumen 104 and the second lumen108. Passing wire 114 in this respect can permit pinching cell 100 toslide along the A-axis, as depicted by arrow S, and rotate about theA-axis, as depicted by arrow R. The A-axis can be defined, for example,aligned with wire 114 or similar implements.

FIG. 2A illustrates an example clot removal device 200 in a deployedconfiguration. The example device 200 can include a microcatheter 202having a lumen 204, a distal end 206, and a proximal end 208. Device 200can include an expandable frame 210 having a distal end 212, a proximalend 214, and one or more frame members 216 a, 216 b, and 216 c. The oneor more frame members 216 a, 216 b, and 216 c can have one or morepinching cells 100 slidably and/or rotatably placed thereon, asdiscussed in FIG. 1B. Device 200 can include an elongated member 218having a distal end 219. The distal end 219 of the elongated member 218can be attached to the proximal end 214 of the expandable frame 210. Theexpandable frame 210 can be constructed from a superelastic materialsuch as Nitinol or an alloy of similar properties.

The material could be in many forms such as wire, strip, sheet and/ortube. A particularly suitable manufacturing process is to laser cut aNitinol tube and then heat set and electropolish the resultant structureto create a framework of frame members. This framework can be any ofhuge range of shapes as disclosed herein and may be rendered visibleunder fluoroscopy through the addition of alloying elements (e.g.,Platinum) or through a variety of other coatings or marker bands. Theelongated member 218 can be a tapered wire shaft, and may be made ofstainless steel, MP35N, Nitinol or other material of a suitably highmodulus and tensile strength. As noted, device 200 can include adelivery configuration for delivery and a deployed configuration forclot retrieval, flow restoration and/or fragmentation protection. Tomove between the delivery to the deployed configurations, expandableframe 210 can be configured to self-expand upon delivery from themicrocatheter 202 (e.g., release from the microcatheter) to a diameterlarger than that of the lumen 204 of the microcatheter 202. In thedeployed configuration, the expandable frame 210 can be distal to thedistal end 206 of the microcatheter 202. The pinching cells 100 can bein an expanded state and a collapsed state, as discussed in greaterdetail in FIGS. 11A-C. In the delivery configuration, the expandableframe 210 can be within the lumen 204 of the microcatheter 202. Turningto FIG. 2B, device 200 is shown in a delivery configuration collapsedwithin the lumen 204 of the microcatheter 202. Further, the pinchingcells 100, can be in a collapsed state, as discussed in detail in FIGS.11A-C.

FIG. 3 is a flow diagram illustrating a method of removing a clot,according to aspects of the present disclosure. The method steps in FIG.3 can be implemented by any of the example means described herein or bysimilar means, as will be appreciated. Referring to method 300 asoutlined in FIG. 3, in step 302, deploying an expandable frame into adeployed configuration from a delivery configuration within a bloodvessel and proximate a clot, the expandable frame can include one ormore frame members and one or more pinching cells located on one or moreframe members. Each of the pinching cells can include a collapsed statewithin a microcatheter and an expanded state distal of the microcatheterconfigured to pinch at least a portion of the clot, the expandable framecan be deployed such that one or more pinching cells are in contact withthe clot. In step 304, advancing a lumen of the microcatheter over theexpandable frame such that a portion of the expandable frame at leastpartially collapses into the lumen of the microcatheter, and one or morepinching cells at least partially collapses into the lumen of themicrocatheter. In step 306, pinching the one or more pinching cells incontact with the portion of the clot on movement from the collapsedstate to a clot pinching state of the expanded state until a portion ofthe clot is compressed between at least a pair of struts of the one ormore pinching cells. Additionally, or alternatively, the pair of strutmembers can be operable to actuate and tweeze the clot from a bloodvessel between the plurality of strut members. Additionally, oralternatively, the pair of strut members are positioned about a centralstrut member, each of the strut members joined at common respectiveproximal and distal ends. In step 308, withdrawing the microcatheter,the expandable frame, and the clot, while pinching the one or morepinching cells withdrawing the microcatheter. Method 300 can end afterstep 308. In other embodiments, additional steps according to theexamples described above can be performed.

FIGS. 4A-C depict a close up of an example clot removal device 200penetrating, pinching capturing a clot 1. In FIG. 4A, device 200 isshown in a deployed configuration with the expandable frame 210 locatedproximate the clot 1 (e.g., embedding with or otherwise contacting theclot). The pinching cell 100 can penetrate the clot 1. In FIG. 4B, themicrocatheter 202, is now sheathed over the expandable frame 210 and thepinching cell 100 causing the pinching cell 100 to pinch a portion ofthe clot 1. Each pinching cell 100 provides enhanced grip on a clot 1,and any fragments thereof. Each of the pinching cells 100 can beparticularly advantageous in capturing clots which may have fibrin corein the center, distal, or proximal location in the clot 1. Moreover, inuse, if grip on some of a clot 1 is missed by one pinching cell 100, oneor more pinching cells 100 distal thereof can engage and/or grip theclot 1. In an example, a portion of the clot 1 can be pinched betweenthe distal end 206 of the microcatheter 202 and the expandable frame210. In FIG. 4C, the clot 1 is captured by the device 200. At least aportion of the clot 1 can be secured by the pinching cells 100 withinthe lumen 204 of the microcatheter 202, now sheathed over the expandableframe 210 and the pinching cell 100. The device 200 can be in thedelivery configuration. Additionally or alternatively, the device 200can be in a securing configuration of the deployed configuration.Additionally or alternatively, the device 200 can be in the pinchingconfiguration of the deployed configuration. Each pinching cell 100provides enhanced grip on a clot 1, and any fragments thereof. Each ofthe pinching cells 100 can be particularly advantageous in capturingclots which may have fibrin core in the center, distal, or proximallocation in the clot 1. Moreover, in use, if grip on some of a clot 1 ismissed by one pinching cell 100, one or more pinching cells 100 distalthereof can engage and/or grip the clot 1.

FIG. 5 illustrates an example pattern of an example expandable frame.The example expandable frame 500 can be helical and include a framemember 502, a distal end 504 and a proximal end 506. The proximal end506 can be configured to connect to the distal end 219 of the elongatedmember 218. One or more pinching cells 100 can be slidably and/orrotatably disposed on the frame member 502. The expandable frame 500 canbe constructed from Nitinol or other suitable materials.

FIG. 6 illustrates an example pattern of an example expandable frame.The example expandable frame 600 can be a double-helix and include afirst frame member 602, a second frame member 604, a distal end 606 anda proximal end 608. The first and second frame members 602, 604 canconnect to one another at the distal end 606 and the proximal end 608.The proximal end 608 can be configured to connect to the distal end 219of the elongated member 218. One or more pinching cells 100 can beslidably and/or rotatably disposed on the first and second frame members602, 604. The expandable frame 600 can be constructed from Nitinol orother suitable materials.

FIGS. 7A-B depict example expandable, non-tubular curved, atraumaticframe patterns capable of being actuated to grip and/or pinch, asbetween one or more peaks of the frame pattern, clot or fragmentsthereof. FIG. 7A illustrates an example expandable frame 700 having aframe member 702, a distal end 704, a proximal end 706. The wave patterncan be defined by a wavelength L1 and an amplitude H1 generallyconsistent between proximal and distal ends. The proximal end 706 can beconfigured to connect to the distal end 219 of the elongated member 218.One or more pinching cells 100 can be slidably and rotatably disposed onthe frame member 702. FIG. 7B illustrates an example expandable frame750 having a frame member 752, a distal end 754, a proximal end 756. Thewave pattern can be defined by a wavelength L2 and a first amplitude H2that can transition into a second amplitude H3 generally larger thanfirst amplitude H2. The proximal end 756 can be configured to connect tothe distal end 219 of the elongated member 218. One or more pinchingcells 100 can be slidably and rotatably disposed on the frame member752. The example expandable frames 700, 750 can be constructed fromNitinol or other suitable materials.

FIGS. 8A-B also depict example expandable, non-tubular frame patternscapable of being actuated to grip and/or pinch, as between one or morepeaks of the frame pattern, clot or fragments thereof. FIG. 8Aillustrates an example expandable frame 800 having a frame member 802, adistal end 804, a proximal end 806. The relatively sharp, non-curvedpattern can be defined by a wavelength L3 and an amplitude H4 that isgenerally consistent between proximal and distal ends. The proximal end806 can be configured to connect to the distal end 219 of the elongatedmember 218. One or more pinching cells 100 can be slidably and rotatablydisposed on the frame member 802. FIG. 8B illustrates an exampleexpandable frame 850 having a frame member 852, a distal end 854, aproximal end 856. The pattern can be defined by a wavelength L4 and afirst amplitude H5 that can transition into a second amplitude H6generally larger than first amplitude H5. The proximal end 756 can beconfigured to connect to the distal end 219 of the elongated member 218.One or more pinching cells 100 can be slidably and rotatably disposed onthe frame member 852. The example expandable frames 800, 850 can beconstructed from Nitinol or other suitable materials.

FIG. 9 illustrates an example clot removal device 900. The device 900can include a clot fragment collection section 902 located at the distalend 212 of the expandable frame 210. The clot fragment collectionsection 902 (e.g., a distal net, mesh, or the like) can be configured toentangle clot fragments that break off the clot 1.

FIG. 10 is a flow diagram illustrating a method of manufacturing a clotremoval device, according to aspects of the present disclosure. Themethod steps in FIG. 10 can be implemented by any of the example meansdescribed herein or by similar means, as will be appreciated. Referringto method 1000 as outlined in FIG. 10, in step 1002, forming one or morepinching cells from a shape-memory alloy tube, each of the one or morepinching cells including a plurality of strut members operable to pincha clot, the plurality of strut members positioned about one or morecentral strut members, each strut member joined at common respectiveproximal and distal ends. Forming the one or more pinching cells canfurther include cutting the shape-memory alloy tube into a plurality ofsegments, cutting a pattern into a segment of the plurality of segments,attaching a radiopaque marker to each of the one or more pinching cells,and shape setting a plurality of strut members and one or more centralstrut members of a pinching structure to memorize an expanded state ofthe pinching structure, the a ratio of diameters of each of the one ormore pinching cells between a collapsed state and the expanded state isfrom approximately 1.5:1 to 4:1. In step 1004, forming at least aportion of an expandable frame, including a proximal end, and one ormore frame members.

Forming at least a portion of the expandable frame can further includeconstructing one or more frame members on a mandrel, shaping, based atleast in part on the mandrel, one or more frame members to memorize adeployed configuration of the expandable frame, and connecting one ormore frame members to form a distal end of the expandable frame. In step1006, assembling the one or more pinching cells with at least a portionof the expandable frame. Assembling the one or more pinching cells withat least a portion of the expandable frame can further include slidingone or more pinching cells over one or more frame members, andconnecting one or more frame members to form a proximal end of theexpandable frame. The one or more pinching cells can be selectivelyaligned in a plurality of orientations. Method 1000 can end after step1006. In other embodiments, additional steps according to the examplesdescribed above can be performed.

FIGS. 11A-C illustrate example pinching cell states. An example expandedstate of the pinching cell 100 is depicted in FIG. 11A. The pinchingstructure 110 has an expanded diameter D1 which can be realized distalof the distal end 206 of the microcatheter 202. An example collapsedstate of the pinching cell 100 is depicted in FIG. 11B. The pinchingstructure 110 has a collapsed diameter D2 which can be realized withinthe lumen 204 of the microcatheter 202. An example pinched state of theexpanded state of the pinching cell 100 is depicted in FIG. 11C. Thepinching structure 110 having a diameter less than the expanded diameterD1, but greater than the collapsed diameter D2. Additionally oralternatively, a ratio of diameters can be calculated by, for example,dividing the expanded diameter D1 by the collapsed diameter D2.Additionally, or alternatively, a ratio of diameters can be calculatedby dividing the collapsed diameter D2 by the expanded diameter D1.

FIG. 12A depicts a close-up view of another example pinching cell 1200 awith strut members 1202 a, 1204 a, and 1206 a now shown with undulatingedges. These undulations can be formed by being heat-set, crimped, orotherwise formed as needed or required. FIG. 12B depicts a close-up viewof another example pinching cell 1200 b with strut members 1202 b, 1204b, and 1206 b each including one or more eyelets. FIG. 12C depicts aclose-up view of another example pinching cell 1200 c with strut members1202 c, 1204 c, and 1206 c now shown with relatively straight,non-curved strut members. FIG. 12D depicts a close-up view of anotherexample pinching cell 1200 d with strut members 1202 d, 1204 d, and 1206d each including one or more notches or indentation. These notches orindentations can be formed by being heat-set, crimped, or otherwiseformed as needed or required.

The disclosure is not limited to the examples described, which can bevaried in construction and detail. The terms “distal” and “proximal” areused throughout the preceding description and are meant to refer to apositions and directions relative to a treating physician. As such,“distal” or distally” refer to a position distant to or a direction awayfrom the physician. Similarly, “proximal” or “proximally” refer to aposition near to or a direction towards the physician.

In describing examples, terminology is resorted to for the sake ofclarity. It is intended that each term contemplates its broadest meaningas understood by those skilled in the art and includes all technicalequivalents that operate in a similar manner to accomplish a similarpurpose. It is also to be understood that the mention of one or moresteps of a method does not preclude the presence of additional methodsteps or intervening method steps between those steps expresslyidentified. Steps of a method can be performed in a different order thanthose described herein without departing from the scope of the disclosedtechnology. Similarly, it is also to be understood that the mention ofone or more components in a device or system does not preclude thepresence of additional components or intervening components betweenthose components expressly identified.

As discussed herein, a “patient” or “subject” can be a human or anyanimal. It should be appreciated that an animal can be a variety of anyapplicable type, including, but not limited to, mammal, veterinariananimal, livestock animal or pet-type animal, etc. As an example, theanimal can be a laboratory animal specifically selected to have certaincharacteristics similar to a human (e.g., rat, dog, pig, monkey, or thelike).

As used herein, the terms “about” or “approximately” for any numericalvalues or ranges indicate a suitable dimensional tolerance that allowsthe part or collection of components to function for its intendedpurpose as described herein. More specifically, “about” or“approximately” may refer to the range of values ±20% of the recitedvalue, e.g. “about 90%” may refer to the range of values from 71% to99%.

By “comprising” or “containing” or “including” or “having” is meant thatat least the named compound, element, particle, or method step ispresent in the composition or article or method, but does not excludethe presence of other compounds, materials, particles, method steps,even if the other such compounds, material, particles, method steps havethe same function as what is named.

It must also be noted that, as used in the specification and theappended claims, the singular forms “a,” “an,” and “the” include pluralreferents unless the context clearly dictates otherwise. Ranges can beexpressed herein as from “about” or “approximately” one particular valueand/or to “about” or “approximately” another particular value. When sucha range is expressed, other exemplary embodiments include from the oneparticular value and/or to the other particular value.

The descriptions contained herein are examples of the disclosure and arenot intended in any way to limit the scope of the disclosure. Whileparticular examples of the present disclosure are described, variousmodifications to devices and methods can be made without departing fromthe scope and spirit of the disclosure. For example, while the examplesdescribed herein refer to particular components, the disclosure includesother examples utilizing various combinations of components to achieve adescribed functionality, utilizing alternative materials to achieve adescribed functionality, combining components from the various examples,combining components from the various example with known components,etc. The disclosure contemplates substitutions of component partsillustrated herein with other well-known and commercially-availableproducts. To those having ordinary skill in the art to which thisdisclosure relates, these modifications are often apparent and areintended to be within the scope of the claims which follow.

What is claimed is:
 1. A clot removal device, comprising: an elongatedmember comprising a distal end; and an expandable frame comprising: aproximal end; and one or more frame members comprising one or morepinching cells operable to be slidably and rotatably placed thereon,each of the pinching cells comprising a collapsed state within amicrocatheter and an expanded state distal of the microcatheter operableto tweeze at least a portion of a clot.
 2. The clot removal device ofclaim 1, the one or more pinching cells comprise: a plurality of strutmembers operable to actuate and tweeze the clot from a blood vesselbetween the plurality of strut members.
 3. The clot removal device ofclaim 2, the plurality of strut members are positioned about one or morecentral strut members, each strut member joined at common respectiveproximal and distal ends.
 4. The clot removal device of claim 2, each ofthe one or more pinching cells operable to tweeze the clot on movementfrom the collapsed state to a clot pinching state of the expanded stateuntil a portion of the clot is compressed between the plurality of strutmembers.
 5. The clot removal device of claim 2, a ratio of diameters ofeach of the one or more pinching cells between the collapsed state andexpanded state is from approximately 1.5:1 to 4:1.
 6. The clot removaldevice of claim 2, each of the one or more pinching cells comprise aradiopaque marker.
 7. The clot removal device of claim 1, the one ormore pinching cells comprise: a pinching structure comprising aplurality of strut members and one or more central strut members; afirst collar comprising a first collar lumen; and a second collarcomprising a second collar lumen.
 8. The one or more pinching cells ofclaim 7, wherein one or more strut members are a network of strutsoperable to tweeze with at least a portion of a clot, the network ofstruts being configured such that in an expanded state at least aportion of the network of struts penetrate the clot.
 9. The one or morepinching cells of claim 7 wherein the first collar lumen and the secondcollar lumen are operable to receive one or more frame members.
 10. Theclot removal device of claim 1, further comprising: an elongated membercomprising a distal end; and wherein the distal end of the elongatedmember is attached to the proximal end of the expandable frame.
 11. Theclot removal device of claim 1, wherein the one or more pinching cellsare selectively aligned in a plurality of orientations on one or moreframe members.
 12. The clot removal device of claim 1, wherein theexpandable frame is generally a wave pattern having an increasingamplitude along its length.
 13. A method for retrieving a clot, themethod comprising the steps of: deploying an expandable frame into adeployed configuration from a delivery configuration within a bloodvessel and proximate a clot, the expandable frame comprising one or moreframe members and one or more pinching cells located on the one or moreframe members, each of the pinching cells comprising a collapsed statewithin a microcatheter and an expanded state distal of the microcatheterconfigured to pinch at least a portion of the clot, the expandable framedeployed such that one or more pinching cells are in contact with theclot; advancing a lumen of the microcatheter over the expandable framesuch that a portion of the expandable frame at least partially collapsesinto the lumen of the microcatheter, and one or more pinching cells atleast partially collapses into the lumen of the microcatheter; pinchingthe one or more pinching cells in contact with the portion of the cloton movement from the collapsed state to a clot pinching state of theexpanded state until a portion of the clot is compressed between atleast a pair of strut members of the one or more pinching cells; andwhile pinching the one or more pinching cells withdrawing themicrocatheter, the expandable frame, and the clot.
 14. The method ofclaim 13, wherein the pair of strut members are operable to actuate andtweeze the clot from a blood vessel between the pair of strut members.15. The method of claim 14, wherein the pair of strut members arepositioned about one or more central strut members, each strut memberjoined at common respective proximal and distal ends.
 16. A method formanufacturing a clot removal device, the method from comprising thesteps of: forming one or more pinching cells from a shape-memory alloytube, each of the one or more pinching cells comprising a plurality ofstrut members operable to pinch a clot, the plurality of strut memberspositioned about one or more central strut members, each strut memberjoined at common respective proximal and distal ends; forming at least aportion of an expandable frame, comprising: a proximal end and one ormore frame members; and assembling the one or more pinching cells withat least a portion of the expandable frame.
 17. The method of claim 16,wherein forming one or more pinching cells from a shape-memory alloytube further comprises the steps of: cutting the shape-memory alloy tubeinto a plurality of segments; cutting a pattern into a segment of theplurality of segments; attaching a radiopaque marker to each of the oneor more pinching cells; and shape setting a plurality of strut membersand one or more central strut members of a pinching structure tomemorize an expanded state of the pinching structure, the a ratio ofdiameters of each of the one or more pinching cells between a collapsedstate and the expanded state is from approximately 1.5:1 to 4:1.
 18. Themethod of claim 16, wherein forming at least a portion of the expandableframe further comprises the steps of: constructing one or more framemembers on a mandrel; shaping, based at least in part on the mandrel,one or more frame members to memorize a deployed configuration of theexpandable frame; and connecting one or more frame members to form adistal end of the expandable frame.
 19. The method of claim 16, whereinassembling the one or more pinching cells with at least a portion of theexpandable frame further comprises the steps of: sliding one or morepinching cells over one or more frame members; and connecting one ormore frame members to form a proximal end of the expandable frame, andwherein one or more pinching cells are selectively aligned in aplurality of orientations.
 20. The method of claim 16, wherein the oneor more pinching cells further comprise: a first collar comprising afirst collar lumen; a second collar comprising a second collar lumen;and wherein the first collar lumen and the second collar lumen areoperable to receive one or more frame members, and wherein the pluralityof strut members and one or more central strut members are a network ofstruts operable to engage with at least a portion of a clot, the networkof struts being configured such that in an expanded state at least aportion of the network of struts penetrate the clot.